Identification and characterization of the role of candidate effectors in the interaction between Bacillus sp. RZ2MS9, a growth-promoting bacterium, and the maize (Zea mays L.)

• Grant number: 19/09665-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2019
• Effective date (End): December 31, 2020
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Maria Carolina Quecine Verdi
• Grantee: Ariane Vitória Silvestre Hannes
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The soaring input of agrochemicals in the production system, in order to increase crop yield, is a reason of concern because the rise in the demand for agrochemicals may endanger the sustainability of agricultural production and the longevity of natural resources. Recent findings on plant growth-promoting rhizobacteria (PGPR) suggest the use of these microorganisms as an alternative to the conventional agricultural practices, in order to reduce possible negative impacts to environment. The strain RZ2MS9 Bacillus sp. was isolated from the rhizosphere of guarana (Paullinia cupana var. sorbilis) and it was able to increase substantially the maize (Zea mays L.) growth. The labeling of this lineage using gfp gene evidenced the endophytic colonization of maize and efficient interaction, and the bacterial genome was sequenced. Effectors are molecules released or associated to an organism that modify another organism's physiology. This definition is based on the fact that not all effectors are molecules that can be secreted by bacteria during the interaction with the host plant. Pathogens can change the defense system of a plant through effectors, that is, molecules that increase the susceptibility of host plants to infection. Effectors can also be related to interactions between beneficial bacteria and host plants, like effectors secreted by gram-negative bacteria from Rhizobium genus. Even its importance in plant-microbe interaction, the role of effectors from PGPR is still incipient. Therefore, the purpose of this project is to select effector candidate molecules from Bacillus sp. strain RZ2MS9 in silico and to promote the knockout of some of these molecules, by CRISPR-Cas9 technique, to investigate and to characterize the function of effector candidates in the interaction between RZ2MS9 and maize.